#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

const int N = 10010, M = 20010;

int n, m;
int h[N], e[M], ne[M], idx;
int q[N], d[N];
int dist[N];

void add(int a, int b) {
    e[idx] = b, ne[idx] = h[a], h[a] = idx ++ ;
}

bool topsort() {
    int hh = 0, tt = -1;
    for (int i = 1; i <= n; ++ i)
        if (!d[i]) q[ ++ tt] = i;
        
    while (hh <= tt) {
        int t = q[hh ++ ];
        for (int i = h[t]; ~i; i = ne[i]) {
            int j = e[i];
            if ( -- d[j] == 0) q[ ++ tt] = j;
        }
    }
    
    return tt == n - 1;
}

int main() {
    cin >> n >> m;
    
    memset(h, -1, sizeof h);
    while (m -- ) {
        int a, b;
        scanf("%d%d", &a, &b);
        add(b, a), d[a] ++ ;
    }
    
    if (!topsort()) puts("Poor Xed");
    else {
        int ans = 0;
        for (int i = 1; i <= n; ++ i) dist[i] = 100;
        for (int i = 0; i < n; ++ i) {
            int t = q[i];
            for (int j = h[t]; ~j; j = ne[j]) {
                int k = e[j];
                dist[k] = max(dist[k], dist[t] + 1);
            }
        }
        
        for (int i = 1; i <= n; ++ i) ans += dist[i];
        
        printf("%d\n", ans);
    }
    
    return 0;
}